纳米硅溶胶加固标准砂三轴试验研究

Triaxial Test Study on Standard Sand Modified by Nano Silica Sol

对不同的养护天数,不同浓度(二氧化硅质量浓度)的纳米硅溶胶固化后的标准砂进行常规三轴固结不排水剪切试验。试验结果表明:试样破坏应力随着浓度和养护天数增大而普遍增大,围压越大,应力达到峰值时应力随应变增大而下降的程度越显著,脆性越强;试样破坏时的偏应力与破坏有效应力随浓度和养护天数的变化可近似用直线表示;试样均是由一开始小阶段的剪缩性转化为剪胀性,浓度越大、养护天数越长,其剪胀性越明显;试样的粘聚力随着养护天数和浓度的增大而增大,内摩擦角随养护天数和浓度的变化规律不显著,其范围值在35.9°～38.4°之间。

The triaxial consolidation undisturbed shear test was carried out on the standard sand modified by Nano silica sol with different curing days and different concentrations(silica mass concentration).The experimental results show that the axial stains at failure increases with the increase of the concentration and the curing days.With the increase of the confining pressure,the stress decreases with the increase of the strain,and the stronger the brittleness is.The deviator stress and the effective stress at failure with the concentration and the curing days can be approximated by a straight line.The sample is from the beginning of a small stage of shear reduction into the greater the shear dilatancy,with the increase of the concentration and the curing days,the more obvious the shear dilatancy.The cohesion of the sample increases with the curing days and the concentration,and the internal friction angle and the curing days,concentration changes Not significant,and its range is between 35.9°and 38.4°.